This invention generally relates to marking apparatus and methods and more particularly relates to an apparatus and method for marking a contoured surface having complex topography with multiple colors.
It is often desirable to place a color image on a three-dimensional object having a complex topography, such as a vase or a human bust statue. Usually this image is applied manually, which is timely and costly. Attempting to quickly apply the image manually to the object typically results in less precision in placement of the image on the object, which is an undesirable result. Therefore, it is desirable to provide a marking device capable of marking such a three-dimensional object having complex topography.
Devices for marking curved surfaces are known. One such device is disclosed in U.S. Pat. No. 5,119,109 entitled: xe2x80x9cMethod And Apparatus For Marking The Inside Surface Of Pipexe2x80x9d, issued Jun. 2, 1992 in the name of John A. Robertson. This patent discloses a system wherein dot matrix characters are formed upon the inside surface of a pipe or other curved surface by an array of ink spray nozzles disposed within a marker head assembly. The marker head is moved by a carriage in a manner such that character pixels are formed during movement of the marker head along loci parallel with the longitudinal axis of the pipe. An indexing mechanism engages an outer surface of the pipe to index it from one marking locus to the next marking locus. Also, a translational mechanism moves the carriage from an off-line to an on-line position during operation of the device. However, this patent does not disclose measuring distance of the surface of the pipe from the marker head before marking begins. That is, this patent does not appear to disclose sensing distance of the surface from the marker head, which may be required in order to sequentially mark pipes having different diameters nor does it disclose printing images of multiple colors. Moreover, use of the Robertson device does not appear to assure uniform placement of ink on a contoured surface having complex topology, such as a vase or a human bust statue.
Therefore, there has been a long-felt need to provide an apparatus and method for suitably marking a contoured surface of complex topology in a manner which automatically determines the contour of the surface and quickly, yet precisely, applies a marking medium uniformly to predetermined portions of the surface and can provide multiple color marking to the surface.
The present invention resides in an apparatus for marking a contoured surface having complex topography. The apparatus comprises a movable color marker for marking the surface and a sensor disposed in sensing relationship to the surface for sensing contour of the surface. A controller interconnecting the marker and the sensor is also provided for actuating the marker and for controllably moving the marker relative to the surface in response to the contour sensed by the sensor, so that the color marker, preferably a multiple color marker, follows the contour of the surface at a predetermined distance therefrom and marks the surface.
An object of the present invention is to provide an apparatus and method for marking a contoured surface having complex topography in a manner which automatically determines the contour of the surface. A further object of the invention is the provision of a method and apparatus for applying multiple colors uniformly to predetermined portions of a contoured surface having a complex topography.
A feature of the present invention is the provision of a sensor for sensing contour of the surface.
Another feature of the present invention is the provision of a controller connected to the sensor for obtaining a three-dimensional map of the surface sensed by the sensor.
An advantage of the present invention is that marking medium is precisely applied evenly on predetermined portions of the surface in a timesaving manner.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention.